Transmitter-hinge.



J. A. BIRSFIELD.

TRANSMITTER HINGE.

APPLICATION FILED MAR. 28, 1907.

Patented Nov. 3, 1908.

5 w J M.

Z01- in eases UNITED STATES PATEN OFFICE.

JULES A. BIRSFIELD, OF CHICAGO, ILLINOIS, ASSIGNOR TQ ALFRED STROMBERG, OF CHICAGO, ILLINOIS.

TRANSMITTER-GE.

Specification of Letters Patent.

?atented Nov. 3, 1908.

Application filed Hatch 28, 1907. Serial No. 364,988.

To all whom it'may concern:

Be it known that 1, Jones A. Bmsrmrn, a citizen of the United States of America, and a resident of Chicago, county of Cook, and State of Illinois, have invented a new and useful Improvement in Transmitter-Hinges, of which the following is a specification.

My invention pertains to hinges for telephone transmitters, and has as its object the production of a device of sightly construction providing a positive hinge and an ample clearance for the conductors passing through the hinge from the transmitter to the fixed terminals rovided in the assembly of apparatus of w ich the transmitter forms a part.

This specification is accompanied by four figures, in which Figure 1 shows a section of my transmitter hinge joint as a plied to the head of a desk stand; Fig. 2 s ows elevation of same; Fig. 3 shows my hinge joint adapted to the requirements ofan o erators breast trans mitter, and Fig. 4 s ows my hinge joint adapted to the requirements of a wall telehone equipment where the transmitter may he mounted upon the face of the box.

Referring to Fig. 1, the assembly of the device as a whole consists of the desk stand cap casting 1, bearing the transmitter 2. The hinge joint consists of three parts: first, a fixed or base part being in this instance the cap piece 1; second, a movable part 101; and third, a clamping member 102; a friction washer 103 also forms an essential feature of the completed hinge.

The casting 1, which is the base casting of the hinge joint, terminates in an annular lip 104 screwthreaded externally; at two points in this annular lip and diametrically opposite each other are semi-circular notches 105.

The second member of the hinge, namely, the movable member, is spherical in that por tion of its external surface which is assembled adjacent to the part 1; the two projecting lugs 106 are adapted to engage the notches 105 of the part 1, and are cylindrical in their enga ing surfaces, with radius approximately t at of the notches 105 so that a smoothly working hinge is obtained. The spherical surface of the part 101 is concentric with the cylinder of the lugs 106 and therefore is revolved upon its center when the part 101 is revolved upon the axis of the lugs 106. The clamping ring 102 is spherical in that portion of its interior surface which engages the part 101, and it is further provi e with internal screw threads to cooperate with the screw threads of the lip 104. The outer extension 107 of the part 101 is sufficiently small to (pass through the clamping member 102, an assembly thus is made by placing the part 101 in position upon the part 1 with the lugs 106 in notches 105, and then passing the clamping ring 102 over the extension 107 and screwing it in place u on the lip 104 to clamp parts 1 and 101 toget er. Part 102 is knurled at 108 to facilitate the assembly, and part 1 is knurled at 109 to improve the appearance of the finished device. [0 secure a smooth hinge movement with uniform friction throughout its range, the leather washer 103 is placed within the clampingflp'art 102 before that clamping part is assem ed in position.

To mount the transmitter 2 upon the extension 107, the extension is drilled and tapped and a screw 110 having a broad fiat head is passed through a perforation in the case of the transmitter 2 and screwed into the extension 107, clamping the transmitter 2 firmly in position. To give the transmitter a greater rigidity than would be secured by mere screw pressure, lugs upon theface of the extension 107 engage corresponding depressions or perforations in the case of the transmitter 2, thus providing an increased resistance to prevent the turning of the transmitter 2 upon the extension 107.

To provide for passing insulated electrical conductors to the working electrical portions of the transmitter 2, the screw 110 1s bored at 111. The part 1 is cast hollow at 112. Passage for conductors thus is provided through the channel 111 and the channel 1 12, the opening through the hinge joint at 105 and 106 being of ample dimension to revent crowdin or twisting or nnduly short ends in the insu ated conductors either in the process of passing them into position or by reason of the operation of the hinge in service.

In Fig. 4 a modification is shown in the substitution of an alternative form of part 1; the part 1" conforms to all the requirements of the part 1 but on the side distant from the hinge the part 1" terminates in a fiat face suitable for mounting upon the door of'a bell box, or other mounting structure of telehone apparatus.

In Fig. 3, the hinge joint of my invention is shown installed between the transmitter 2' of an operators breast set and the mouthpiece 3 of the transmitter. The part 101' and mouthpiece 3 are shown in section. The transmitter case 2 has the integial' projecting neck 1 upon which the mout piece 3 1s hinged. This part is given the label 1 since, so far as a consideration of the hinge 'oint is concerned, it corres onds to part 1 of i s. 1 and 2 and part 1 0 Fig. 4.

do not wish to limit myself in all respects to the exact details herein illustrated and described, as I understand that modifications may be made without departing from the spirit or sco e of my invention.

Having tus described my invention, what I claim as new and desire to secure by United States Letters Patent is:

1. A hinge comprising a movable member having a spherica convex surface, said surface being cut awayto leave two diametricall opposite pro'ections lying within the sp ere of the su ace; a fixed member engaged by the two projections of said movab e member; and means for retaining said members in contact, substantially as described.

2. A hinge comprising a movable member having a spherica convex surface, said surface being cut away to leave two diametric- 3. A hinge comprising a movable member having a spherica face being cut away to leave two diametricall opposite projections lying within the sp ere deternuned by the surface; a fixed member having two grooves for engagement by the rojections of said movable member, the su ace of the grooves and the surface of the pro'ections being surfaces of revolution about t e axis of the hinge; and means for holding said parts in contact, substantially as described. I

Signed by me at Claim 0, county of Cook and State of Illinois, in t e presence of two witnesses.

JULES A. BIRSFIELD.

convex surface, said sur-' 

